DIVERTICULA OF THE ALIMENTARY TRACT

DIVERTICULA OF THE ALIMENTARY TRACT

  1. 1
    Current Diagnosis

    • Endoscopy or barium swallow study may be used in the evaluation of most upper alimentary tract diverticula.

    • Symptomatic small intestinal diverticula are difficult to diagnose and require a high index of suspicion and radiographic examination (nuclear medicine scans, capsule endoscopy, or computed tomography scans).

    • Diverticulitis of the colon is most accurately identified and the treatment planned with computed tomography of the abdomen and pelvis.

    • Diverticulitis of the colon that is slow to resolve may require additional imaging or direct visualization with endoscopy to identify an alternative diagnosis.

  2. 2
    Current Therapy

    • Most asymptomatic diverticula are identified incidentally and may only require monitoring.

    • Surgical management of symptomatic diverticula may require surgical resection or endoscopic stenting.

    • Early in the disease process, uncomplicated diverticulitis of the colon may be managed on an outpatient basis with a conservative no-intervention approach or oral antibiotics.

    • Complicated diverticulitis of the colon should be managed in conjunction with a surgeon and in the hospital with intravenous antibiotics.

    A diverticulum is an abnormal saccular protrusion from the wall of the alimentary tract. Diverticula may be classified as either true or false. The wall of the alimentary tract is composed of submucosal, mucosal, and muscular layers. A false diverticulum is a protrusion of the submucosa and mucosa through a defect in the muscular wall of the alimentary tract. A true diverticulum is a protrusion of all layers of the alimentary tract wall. Many diverticula are asymptomatic and require no treatment. Some diverticula cause symptoms depending on their anatomic location or associated pathophysiologic complications (e.g., obstruction, infection, inflammation, or bleeding). This chapter categorizes alimentary canal diverticula by their location.

  3. 3
    Esophagus

    Zenker’s Diverticulum

    Zenker’s diverticulum is a false diverticulum that develops in the upper posterior esophagus in an area known as Killian’s triangle, located between the inferior pharyngeal constrictors and the cricopharyngeal muscles. Zenker’s diverticulum typically presents after age 60 and has a male predominance for reasons that are unclear. It affects only 2 per 100,000 patients per year. Though it can be asymptomatic for years before the development of symptomatology, patients may experience dysphagia, aspiration, and regurgitation of undigested food. The exact cause is unclear, but proposed mechanisms suggest a dysfunction in coordinated swallowing muscle movement and increased intraluminal pressure in the esophagus.

    There may be an additive component of long-term upper esophageal sphincter irritation from acid reflux.

    Diagnosis is primarily made through barium swallow, though small diverticula may be missed (Figure 1). Although endoscopic direct visualization is possible, caution should be exercised owing to the risk of perforation. Small asymptomatic diverticula can be monitored.

    Zenker’s diverticulum greater than 2 cm in size, regardless of symptomatology, should be surgically evaluated and repair considered. Methods for closure include endoscopic diverticulostomy and myotomy or traditional surgical resection. Although most patients (> 90%) demonstrate symptom improvement, recurrence rates can be as high as 35%.

    FIGURE 1    Zenker’s diverticulum. (Image courtesy of Gastrolab—The Gastrointestinal Site. Available at http://www.gastrolab.net [accessed August 25, 2014].)

    Traction Diverticulum

    Traction diverticula are the only true diverticula of the esophagus. Traction diverticula are rare. Their size tends to stay below 2 cm.

    Owing to the mechanism of formation, traction diverticula are isolated to the middle third of the esophagus. It is not fully clear how traction diverticula form. One proposed mechanism is related to a precedent pulmonary infection, most commonly tuberculosis or histoplasmosis, with resultant mediastinal lymph node formation. After the active infection subsides, resultant fibrosis and scarring between the tissues surrounding the mediastinal lymph nodes and esophagus occur.

    Initially, a small diverticulum develops from this fibrosis, which produces “traction” or a lack of mobility. Diverticular progression results when age-related changes from the dysfunction of coordinated swallowing muscle movement and increased intraluminal pressure in the esophagus develop. Surgical management is rarely needed unless these diverticula become symptomatic or complications, such as fistulas, occur.

    Epiphrenic Diverticulum

    Epiphrenic diverticula are false diverticula of the distal esophagus affecting only 0.015% of the general population. They are thought to arise secondary to mucosal injury from gastroesophageal reflux and muscle dysmotility. They occur within 10 cm of the gastroesophageal junction, and symptoms include dysphagia, spasmodic chest pain, and gastroesophageal reflux. With progression of diverticular size,

    obstruction can become a potential complication. Diagnostic measures start with barium swallow and may be followed with additional tests, including endoscopy, 24-hour pH probe, and esophageal manometry.

    Management depends on patient symptoms and size of the diverticulum. If small (< 5 cm) and asymptomatic, routine clinical and endoscopic surveillance is permissible. However, any symptomatology necessitates surgical evaluation and repair. Surgical options include open resection and laparoscopy. Partial fundoplication may be indicated depending on the severity of gastroesophageal reflux present as indicated by ancillary testing of the 24-hour pH probe.

  4. 4
    Stomach

    Gastric Diverticula

    Gastric diverticula are rare with an endoscopic incidence of 0.01%. Most are asymptomatic and small (< 3 cm). Symptoms may include epigastric pain, dyspepsia, and emesis. Rarely, ulcerations, perforations, or bleeding can occur. Diagnosis involves endoscopy, barium swallow, or contrast-aided computed tomography scan. If symptomatic, typical treatment includes a proton pump inhibitor and monitoring for symptom improvement. Persistent symptoms may necessitate gastrectomy of the diverticulum.

  5. 5
    Small Intestine

    Duodenal Diverticula

    Diverticula located in the duodenum are relatively common, affecting up to 22% of the general population (Figure 2). Duodenal diverticula may be either true or false diverticula. The most common location is the second portion of the duodenum. The size and position of the diverticula may lead to complications such as obstruction of the sphincter of Oddi and/or impingement of the hepatobiliary tree drainage. This impingement may result in jaundice, right upper quadrant pain, or infection signs/symptoms similar to cholecystitis.

    Although usually asymptomatic, on occasion ulcerative bleeding or perforation may occur.

    FIGURE 2    Duodenal diverticulum. (Image courtesy of Gastrolab—The Gastrointestinal Site. Available at http://www.gastrolab.net [accessed August 25, 2014].)

    Duodenal diverticula may be identified on barium swallow, contrast-enhanced computed tomography, magnetic resonance imaging, or endoscopy. Duodenal diverticula found incidentally do not require treatment. If symptoms arise, endoscopic evaluation and surgical resection should be considered. However, intervention should be considered with caution owing to a high risk (30%) of complications, in particular fistula formation and mortality.

    Jejunal and Ileal Diverticula

    Jejunal and ileal diverticula occur throughout the length of the small intestine in about 1% to 2% of the population. There does not appear to be any statistically significant relationship with morbidity or mortality of these types of diverticula with respect to location, gender, size, number, and so forth. These false diverticula are located predominantly where the blood vessels penetrate the muscular wall of the mesenteric side of the bowel. Most are noted incidentally, but some manifest with symptoms secondary to bleeding, obstruction, or infection. These symptoms are believed to be due to bacterial overgrowth that may occur within the cavity of the diverticulum.

    Diagnosis can be made with capsule endoscopy or a small bowel barium contrast follow-through study, although some may be noted on computed tomography with intravenous and oral contrast.

    Asymptomatic jejunal and ileal diverticula should not be resected. Bacterial overgrowth symptoms may respond to antibiotic treatment and intestinal promotility drug therapy. Surgical intervention with small bowel resection is indicated if symptomatic diverticula persist.

    Meckel’s Diverticulum

    Meckel’s diverticulum is a congenital anomaly that occurs owing to incomplete closure of the vitelline duct. This duct typically obliterates during the ninth week of gestational age. Owing to the embryologic origin of the diverticulum, it is almost always located within 2 feet of the ileocecal valve. Meckel’s diverticulum has a prevalence of approximately 1% to 2% of the population, with a 2:1 male predominance. About 2% of all existing Meckel’s diverticula will become symptomatic. Symptomatic diverticula most commonly cause nausea, vomiting, and abdominal pain. The sign most commonly associated with Meckel’s diverticulum is intussusception. This occurs owing to residual fibrous attachments to the umbilicus causing a lead point for the proximal bowel to involute onto the distal bowel. It most commonly presents with bloody mucoid stools, abdominal pain, and vomiting in children under age 6. However, other symptoms may occur if ectopic tissue exists in the diverticulum. Gastric ectopic tissue may cause abdominal pain and bloody stools from ulceration of the underlying ileal tissue. Duodenal and pancreatic tissues have been identified in Meckel’s diverticulum but are very rare and do not typically cause symptoms.

    Diagnosis in adults requires a high level of suspicion and is aided by the use of a technetium 99 m (99mTc) scan to identify ectopic gastric mucosa in those patients with bleeding and symptoms of ulceration. For children with obstructive signs or symptoms, the diagnosis may be aided by ultrasound and/or computed tomographic scans. Plain film radiographs of the abdomen have low sensitivity and specificity for the diagnosis of intussusception. The sensitivity of the Meckel scan for the pediatric population is 85% to 97% but is much lower in the adult population at 62%. The choice of imaging procedure is dictated by the experience of the radiologic personnel performing the procedure.

    Symptomatic Meckel’s diverticulum should be surgically resected.

    Up to 90% of intussusception secondary to Meckel’s diverticulum may be reduced during diagnostic ultrasonography in children. Treatment of Meckel’s diverticulum largely depends on age and symptomatology because operating on asymptomatic Meckel’s diverticulum has been shown to have a fivefold increase in complications, such as postoperative bowel obstruction, leaks, ileus, and infection. Many experts have advocated that incidental, asymptomatic Meckel’s diverticulum should not be resected. Some experts advocate for selective surgical resection of asymptomatic patients with an incidentally noted Meckel’s diverticulum for the following: healthy young children, healthy adults younger than 50 years of age with palpable abnormalities suggestive of heterotrophic tissue, size longer than 2 cm, or a broad base wider than 2 cm.

     

  6. 6
    Colon

    Diverticulosis

    The colon is where the majority of all diverticula occur in the alimentary tract. Owing to this predominance, this condition is commonly termed diverticulosis or diverticular disease. Diverticulum of the colon is of the false type. The incidence increases with age. The incidence of left-sided diverticulosis approaches 5% at age 40 and increases to greater than 60% at age 80. Diverticulosis is most commonly located in the sigmoid colon.

    The exact pathogenesis of diverticulosis is unclear. The proposed mechanism of colonic diverticular formation places an emphasis on intraluminal pressure buildup. The pressure across the colonic wall increases as the radius of the wall decreases. Accordingly, the radius is the smallest in the sigmoid colon and thus the most likely location of diverticulosis. Normally, pressure is constant throughout the colon. However, as diverticular disease develops, abnormal pressure segmentations occur resulting in pressure gradient changes in the colon. With increased pressure, the integrity of collagen and elastin in the wall muscle changes, the circular muscles thicken, colonic segments shorten, and the lumen narrows, leading to propagation of the disease. Several risk factors have been associated with the development of diverticular disease: smoking, lack of physical activity, and obesity. By increasing the amount of dietary fiber, it is theorized that the resultant bulking of the stools may decrease the pressure in the colon lumen and prevent diverticular disease progression. Yet, mixed results have been noted on studies with regard to fiber intake and diverticular development and progression of disease.

    Colonic Diverticular Bleeding

    Diverticula tend to develop where an arteriole penetrates the circular muscle layer of the colon. This results in vessels arching over the dome of the diverticulum. This leaves fragile vessels in a vulnerable position of a relatively thin mucosal layer prone to trauma and resultant diverticular bleeding. Bleeding typically manifests as hematochezia—a darkish to bright red bleeding that is typically characterized as brisk and acute in nature. Diverticulosis is attributed to 30% to 50% of all hematochezia. Fifteen percent of patients will experience at least one episode of bleeding in their lifetime, with a recurrent bleeding risk of up to 38%. Most patients presenting with diverticular bleeding are asymptomatic, but some may experience bloating or cramping.

    Selection of the diagnostic modality depends largely on the degree of bleeding and the cardiovascular stability of the patient. Although new technologies are emerging with enhanced computed tomography scanning, their availability is not widespread. Endoscopy is the preferred treatment modality for stable patients owing to its potential for diagnosis and treatment options. Up to 80% of diverticular bleeding can be isolated with direct endoscopic visualization (Figure 3).

    FIGURE 3    Colonoscopy in a patient with hematochezia from  the source isolated to a diverticulum (A) and hemostasis noted after placement of two hemoclips (B). (Courtesy of Janak Shah.) (From Feldman M: Sleisenger and Fordtran’s Gastrointestinal and Liver Disease, 9th ed. Philadelphia,Elsevier, Figure 117-8.)

    Endoscopic failure to identify or control diverticular bleeding may occur in the patient with massive or intermittent bleeding. Hemodynamically unstable patients may have a high complication risk from the bowel preparation, sedation, or the procedure.

    Radionuclide imaging can be considered in unstable patients, nondiagnostic endoscopy, or bleeding recurrence. Radionuclide imaging requires that bleeding be active (at least 0.05–0.1 mL/min) to accurately isolate the location of the diverticulum. Radionuclide imaging using technetium (99mTc) sulfur colloid (shorter half-life thus utilized for acute bleeding) or 99mTc pertechnetate (longer half-life more useful for intermittent bleeding)–labeled autologous red blood cells can be used to isolate the location of obscure gastrointestinal bleeding. However, numerous studies have produced highly variable sensitivities (26% to 91%). Many advocate for radionuclide imaging to be used as an ancillary test for directing more definitive treatments such as surgery or angiography-directed therapies. Angiography can be used if bleeding is active (at least 0.5 mL/min) and can isolate the bleeding location with a diagnostic yield of 40% to 78%. Angiography can be combined with embolization and/or vasopressin infusion to achieve hemostasis; however, complications may occur, including bowel infarction and contrast-induced nephrotoxicity.

    Diverticulitis

    Diverticulosis is largely asymptomatic. Only about 4% will develop inflammation and infection known as diverticulitis. The disease severity and complications occur along a spectrum. The proposed mechanism of diverticulitis may be a blocked diverticulum or trauma- associated mucosal injury. Colonic diverticula become filled with feces and obstruction may occur. With the resultant bacterial overgrowth, expansion of the diverticula occurs. Subsequent vascular compromise and microperforation may occur, leading to localized infection and inflammation. These microperforations are usually sequestered and may lead to small localized abscess formation. This process is generally referred to as uncomplicated diverticulitis.

    Complicated diverticulitis is classified when a localized abscess or infection infiltrates into adjacent organs or viscera causing macroperforations, fistulas, obstructions, or enlarged abscesses.

    The clinical presentation often begins with mild left lower abdominal pain, fever, and leukocytosis. Patients who seek care later in the disease process may present with sepsis or diffuse peritonitis. Initial diagnosis should be accomplished with history, physical examination, radiographic imaging, and laboratory evaluation.

    Abdominal radiography may indicate severe complications of diverticulitis such as bowel perforation or bowel obstruction. Ultrasonography and magnetic resonance imaging can be used with high levels of sensitivity and specificity in centers with demonstrated expertise. Ultrasonography has sensitivities and specificities of 92% and 90% for the detection of diverticulitis, respectively. With sensitivities and specificities of 94% and 99%, respectively, computed tomography appears to be the imaging test of choice. This is especially true as an alternative diagnosis was more likely to be identified with computed tomography than with ultrasonography (50%–100% vs.33%–78%). Those patients with a past medical history of diverticulitis may be empirically treated without imaging, although imaging may be needed if no clinical improvement is noted within 48 hours.

    Recent data indicates no added benefit with antimicrobial therapy; thus uncomplicated diverticulitis may be treated without antibiotics. Until further studies are done, many experts recommend that traditional treatment should include supportive care and antibiotics for uncomplicated diverticulitis. Outpatient management is reasonable if the diagnosis is made early in the disease process.

    Uncomplicated diverticulitis responds to medical therapy in the majority of cases. Complicated diverticulitis occurs in 25% of all diverticulitis diagnoses, requiring a surgical evaluation and intervention. Optional antibiotic regimens for gram-negative coverage and anaerobic coverage are listed in Table 1. Inpatient management is recommended with any comorbid conditions, immunosuppression, high-grade fever, or leukocytosis and/or for elderly patients. Patient improvement should be seen within 48 hours. Those who do not improve should undergo additional evaluation such as repeat imaging or endoscopy. This is done to evaluate for underlying pathology such as cancer or inflammatory bowel disease, which would change the management strategy.

    Table 1

    Antibiotic Therapy for Diverticulitis

     

    Modified from Jacobs DO. Clinical practice. Diverticulitis. N Engl J Med   2007;357:2057–2066.

    Notes: Clindamycin (Cleocin) may be substituted in metronidazole intolerance/allergy. Antibiotics continued in complicated diverticulitis cases until negative cultures, clinical improvement, or sensitivities obtained on any surgical  specimens.

    Abbreviations: bid = twice a day; tid = three times a  day.

    1  Not FDA approved for this indication.

    Follow-up scanning should also be considered for cases of slow-resolving diverticulitis. In up to 10% of computed tomography scans in which diverticulitis was the primary diagnosis, cancer could not be fully excluded. A colonoscopy should be performed to evaluate the extent of diverticular disease and to rule out other comorbid pathology in all patients. Colonoscopy is typically recommended within 3 to 6 weeks after diverticulitis symptoms have resolved.

    Introduction of stool softeners and a high-fiber diet should begin immediately and continued indefinitely for all patients to help decrease the intraluminal pressure within the colon.

    Diverticulitis that is complicated with abscess formation should be evaluated by a surgeon or radiologist for percutaneous drainage using computed tomography or ultrasonography (Figure 4). Depending on location, drainage tubes may be placed transanally for drainage. A general recommendation exists for consideration of drainage, preferably with interventional radiology localization, for any abscess measuring greater than 3 to 4 cm.

    FIGURE 4    Diverticulitis. A, Computed tomography (CT)  image demonstrates thickened wall of the sigmoid colon (arrows) with stranding in the adjacent fat (*) indicative of diverticulitis. Fat stranding refers to abnormally increased attenuation of fat from edema and engorgement of lymphatics. B, CT image slightly more caudal demonstrates an air-filled abscess cavity (arrows) with adjacent thickened sigmoid colon wall. (From McNally PR: GI/Liver Secrets Plus, 4th ed.

    Noninvasive Gastrointestinal Imaging: Ultrasound, Computed Tomography, Magnetic Resonance Imaging. Philadelphia, Mosby Elsevier, 2010, Figure 70–16.)

    New research to prevent recurrent diverticulitis with medical management is emerging. Mesalamine (Asacol)1 and rifaximin (Xifaxan),1 in combination or separately, may help prevent recurrent episodes of diverticulitis. Probiotics7 have not been shown to prevent recurrence. Fiber may be used as a beneficial supplement for the prevention of recurrent diverticulitis. Debate exists regarding elective segmental colectomy for patients who have experienced recurrent episodes of diverticulitis. Current recommendations suggest surgical consultation with discussion of the benefits and risks of surgery compared to the risks of recurrent diverticulitis. This discussion should take into account the diverticulitis frequency and severity, the impact on the patient’s lifestyle, and the patient’s other comorbid conditions. This consultation should at a minimum occur after the fourth recurrence of diverticulitis in patients over age 50. There is insufficient evidence to advise a patient who has experienced fewer than four recurrent cases of diverticulitis or who is younger than age 50 on the benefit of a segmental colectomy.

  7. 7
    References

    Choi J.J., Ogunjemilusi O., Divino C.M. Diagnosis and management of diverticula in the jejunum and ileum. Am Surg. 2013;79(1):108–110.

    Delavux M. Diverticular disease of the colon in Europe: Epidemiology, impact on citizen health and prevention. Aliment Pharmacol Ther. 2003;18(Suppl 3):71–74.

    Fry R.D., Mahmoud N.N., Maron D.J., Bleier J.I.S. Colon and rectum. In: Townsend Jr., D.Beauchamp C.M., eds. Sabiston Textbook of Surgery. ed 19th Philadelphia: Saunders; 2012:1309– 1314.

    Greene C.L., McFadden P.M., Oh D.S., et al. Long-term outcome of the treatment of Zenker’s diverticulum. Ann Thorac Surg.

    2015;100:975–978.

    Jacobs D.O. Clinical practice. Diverticulitis. N Engl J Med.

    2007;357:2057–2066.

    Janes S.E., Meagher A., Frizelle F.A. Management of diverticulitis. BMJ. 2006;332:271–275.

    Kilic A., Schuchert M.J., Awais O., et al. Surgical management of epiphrenic diverticula in the minimally invasive era. JSLS.

    2009;13:160–164.

    Laméris W., van Randen A., Bipat S., et al. Graded compression ultrasonography and computed tomography in acute colonic diverticulitis: Meta-analysis of test accuracy. Eur Radiol.

    2008;18:2498–2511.

    Lin S., Suhocki P.V., Ludwig K.A., Shetzline M.A. Gastrointestinal bleeding in adult patients with Meckel’s diverticulum: The role of technetium 99 m pertechnetate scan. South Med J. 2002;95:1338.

    Maish M.S. Esophagus. In: Townsend Jr., D.Beauchamp C.M., eds. Sabiston Textbook of Surgery. ed 19th Philadelphia: Saunders; 2012:1023–1025.

    Martinez-Cecilia D., Arjona-Sanchez A., Gomez-Alvarez M., et

    1. Conservative management of perforated duodenal diverticulum: A case report and review of the literature. World J Gastroenterol. 2008;14:1949–1951.

    Mohan P., Ananthavadivelu M., Venkataraman J. Gastric diverticulum. CMAJ. 2010;182:E226.

    Morris A.M., Rogenbogen S.E., Hardiman K.M., Hendren S. Sigmoid diverticulitis: A systematic review. JAMA.

    2014;311:287–297.

    Mulder C.J., Costamagna G., Sakai P. Zenker’s diverticulum: Treatment using a flexible endoscope. Endoscopy. 2001;33:991– 997.

    Oukachbi N., Brouzes S. Management of complicated duodenal diverticula. J Visceral Surg. 2013;150:173–179.

    Park J.J., Wolff B.G., Tollefson M.K., et al. Meckel diverticulum: The Mayo Clinic experience with 1476 patients (1950–2002). Ann Surg. 2005;241:529–533.

    Sartelli M., Catena F., Ansaloni L., et al. WSES Guidelines for the management of acute left sided colonic diverticulitis in the emergency setting. World J Emerg Surg. 2016;11:37.

    Shahedi K1., Fuller G., Bolus R., et al. Long-term risk of acute diverticulitis among patients with incidental diverticulosis found during colonoscopy. Clin Gastroenterol Hepatol. 2013;11(12):1609–1613.

    Shabanzadeh D.M., Wille-Jørgensen P. Antibiotics for uncomplicated diverticulitis. Nov 14; Cochrane Database Syst Rev. 2012;11:doi:10.1002/14651858.CD009092.pub2 Art. No.: CD009092.

    Sinha C.K., Pallewatte A., Easty M., et al. Meckel’s scan in children: A review of 183 cases referred to two paediatric surgery specialist centres over 18 years. Pediatr Surg Int. 2013;29:511–517.

    Strate L.L. Lower GI, bleeding: Epidemiology and diagnosis.

    Gastroenterol Clin North Am. 2005;34:643–664.

    Verdonck J., Morton R.P. Systematic review on treatment of Zenker’s diverticulum. Eur Arch Otorhnolaryngol. 2015;272:3095–3107.

    Weizman A.V., Nguyen G.C. Diverticular disease: epidemiology and management. Can J Gastroenterol. 2011;25:385–389.

    Zani A., Eaton S., Rees C.M., et al. Incidentally detected Meckel diverticulum: To resect or not to resect? Ann Surg. 2008;247:276–281.

    1  Not U.S. Food and Drug Administration (FDA) approved for this   indication.

    7  Available as dietary supplement.

KNOWLEDGE BASE
About Genomic Medicine UK

Genomic Medicine UK is the home of comprehensive genomic testing in London. Our consultant medical doctors work tirelessly to provide the highest standards of medical laboratory testing for personalised medical treatments, genomic risk assessments for common diseases and genomic risk assessment for cancers at an affordable cost for everybody. We use state-of-the-art modern technologies of next-generation sequencing and DNA chip microarray to provide all of our patients and partner doctors with a reliable, evidence-based, thorough and valuable medical service.

X